NUTRIENT CONTENTS, RUMEN PROTEIN DEGRADABILITY AND ANTINUTRITIONAL FACTORS IN SOME COLOR-FLOWERING AND WHITE-FLOWERING CULTIVARS OF VICIA-FABA BEANS

Six colour-flowering (Scirocco, Alfred, Carola, Condor, Tina and Herz Freya) and six white-flowering (Caspar, Albatros, Gloria, Tyrol, Vasco and Cresta) cultivars of Vicia faba were studied. The crude protein c ontents of colour-and white-flowering cultivars were 267 +/- 13.6 and 283 +/- 18.8 g kg(-1), respectively, which did not differ significantl y at P < 0.05. The levels of lipids, crude fibre, starch and ash varie d from 14 to 22 g kg(-1), 88 to 143 g kg(-1), 407 to 485 g kg(-1) and 32 to 42 g kg(-1), respectively. The calculated organic matter digesti bility (OMD) and metabolisable energy (ME) of the white-flowering cult ivars were significantly higher (P < 0.001) than those of the colour-f lowering cultivars (OMD: 889.1 +/- 26.6 g kg(-1) vs 797.5 +/- 17.1 g k g(-1); ME: 13.97 +/- 0.49 vs 12.30 +/- 0.34 MJ kg(-1)). In all cultiva rs, sulphur amino acids were lower than adequate concentration when co mpared with recommended amino acid pattern of FAG/WHO/UNO reference pr otein for a 2-5-year-old child. The in vitro rumen nitrogen degradabil ity of colour-flowering cultivars was significantly lower (P < 0.01) c ompared to that of white-flowering cultivars (71.4 +/- 9.3% vs 88.0 +/ - 11.1%). Amongst colour-flowering varieties, the contents of total ph enols (TP), tannins (T) and condensed tannins (CT) were highest in Alf red (28.3, 21.0 and 35.4 g kg(-1), respectively). The contents of TP a nd T were similar (about 15 and 10 g kg(-1), respectively) in Carola, Tina and Herz Freya, and the CT were in the order: Condor > Herz Freya > Carola. The CT were not detected in white-flowering varieties, T we re virtually absent and TP were extremely low (4.0-4.9 g kg(-1)). The activities of other antinutritional factors (white- and colour-floweri ng cultivars, respectively: trypsin inhibitor activity 3.05 +/- 0.34 a nd 1.85 +/- 0.09 mg trypsin inhibited g(-1); lectin 27.2 +/- 9.4 and 2 7.1 +/- 5.1 mg ml(-1) assay medium producing haemagglutination; phytat e 15.0 +/- 2.7 and 16.6 +/- 2.3 g kg(-1)) were very low. A strong nega tive correlation (r = -0.92, P < 0.001) between tannins and in vitro r umen protein degradability was observed which suggested that tannins h ave adverse effect on protein degradability. Similarly negative correl ations between tannin levels and metabolisable energy (r = -0.89; P < 0.001) and organic matter digestibility (r = -0.89; P < 0.001) were ob served. The correlation coefficient between trypsin inhibitor activity and tannins was negative and highly significant (r = -0.88, P < 0.001 ), whereas between tannins and saponins it was significantly positive (r = 0.96, P < 0.001).